Pipe-bending machine



Mgrch l5, 1932. C. FRANCIS 1,849,181

PIPE BENDING MACHINE Filed March 26, 1930 FIG.|

CHARLES FRANCIS A7' NEY Patented Mar; 15, 1932 In vforming bends'frorn large and heavy pipe by power it has heretofore been known to support the pipe byy Ineans of idler rolls,l to hold the free end ofthe pipe in a clampk attached to a rotatable head` and, by vrotating such head in a fixed position las regards the idler rolls, to bend the pipe to a desired radius by forcing it against affixed.y to the h Ametal. and into yCHARLES. Immersion WALNUT PARK, CALIFORNIA y i IBE-BENDNG MACHINE j Y fAppncation'iedMarch 26, 193esemiNofeaaoie.

ead.

heretofore proposed a cost exceeding" that of" Y lbending machineV itself.

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I have discovered that it is not necessaryto inake the-'circumferential curvature 'of the segments of a divided die exactly'correspond to the: curvatureofthe desired bend but that, on the contrary, smooth bends free al, from kinks or flats may be made by usinga pluralityof dieshaving a much shorter radius than 'that of the desiredbend, by Vradially advancing such dies untiltheir high' or [center points coincide with the arc described bend to be made.v s

Giving this ina diagramm ings Vdiscovery ypractical 'application, I utilize it inga bending machine which may be constructed as in the :attached'draw ings,yin which rnyiinprovement is shown lin detail while the bending machine 'itself, whichfis moreor less conventional, isshown atic manner. 1Ink these dr blocks or dies also p ks beingunitary or substan-I tially so it is necessary to provide such al block or set of blocks, notonly for eachV size of pipe to be bent but also'r for each radius. of bend to b e made. Thus the equipment of dies :required fora variety of pipe sizes andr bend radii will often run. into a `great weightof "Fig l is a side elevationof the complete Vmachine, showing the dies in the saine inan- Fig. Qis a and p* Fig .'3 is across-section'through a preferred forinofsegmentaldie rightfendr yelevation ofy 1';

the

This franieinay desirably be biiilt of channel or other suitable'steel` sections, andinaybevr bolted Vor welded together, the" latter con? struction giving great sti'ness and strengthi cast-iron or" other vfrainey mayrbeused if preferred.

platesbylthebolts y15 a'ndniay be inoved up or down, by loosening these bolts, to vbring the idler rolls 16and 16B into -a tangent of the ibendtO be made. '1 v These idler vrolls are carried in the'channels on pinsl7,-which should be readilvrevtially fit the size pipe lto be bent.

A.V faceplate 19, which Win be wither-aethe powerfully, as by any train pof'gears-QOA actu*- I'eferringto Figs; l andZ, the ineinbers l() A form av` frame on which the working parts are j `assembled and by which they are supported.

ll-ll Iare rigid plates having vertical slots l2 and attached tothe'fraine'as at 13. The` U-channel 14- is heldv in Contact with these o vmovable,and are grooved as at 18 tojsub'stanscribed, is arranged to be revolved slowly and0 A ated by a source ofpower, as therelectri'c'rnoy e tor'2l.' In FiglfQ the faceplate ijsshown as integi/"a'lwith` the last` gearinv the train,but" it may be supported' and revolved in any'suit- 'able or'preferred manner, thisbeing no part f ofrny present invention. 'l f center of revolution of the face plate, is eX ceedingly high and I propose tosupportv this 'Y roll at its outer end by means ofV a stub shaft the l 39 projecting from the center of the' face plate of the shaft, and bolts 42 attaching the lower end of this strap to a convenient part-"of the channel lil.' This strapmay be removedin caselit interferes with placing the vpipe in aw'- the idler'rolls.)l 4 i f Y '(1 'L To the face plateis' attached aclamp 22f0r In forming a bend the strain on the' idler i i roll1l6B,"which issit'uated directly below the i9, a strap 40 carrying at its upper 'end'a bcaring box 4:1 adapted to slip freely over the end A holding the free end of the pipe. This clamp may be of any preferred design but it must be movably attached to the face of the plate, as for instance by the apron 23 having a slot 2a through which bolts 25 may be passed into holes formed in the face plate, the slot permitting the bolts to be given any required spacing. This clamp should hold the pipe at such distance from the face plate as to bring it into alignment with the groove in the dies about to be described.

To the face of the plate I attach a plurality of segmental dies Q6, having a circumferential curvature 27 which is an arc of the closest bend for which the dies are to be used. Thus in llig. l the curX-*a-ture of the face 27 is an arc of the circle 28 described by the faces ofthe dies when they are fully retracted and brought into side contact.

The dies may be affixed to the face plate in any preferred manner, as for instance by bolts passed through holes 29 in the plate and holes` -O in the die. The holes'in the plate may be radially arranged and the radii so spaced that when the dies are fullyV retracted toward the center of revolution they willy be substantially in side contact. The arrangement of the holes is also such that they form circles about the center of revolution. Such radial. and circular arrangement is indicated at 31-31 in Fig. l. Jintervening rows falling in circles of intermediate diameter as at 32-32 may also be Aformed to permit closer adjustment of the radius of the bend. lf preferred, slots maybe substituted .for rows of holes as shown, though this is less desirable as requiring greater care in settingthe dies and as materially weakening the face plate, as well as incurring danger of one or more of the rdies slipping inward under the intense stress incident to the formation of a bend from heavy pipe.

A The Vdies may have the cross-section 'shown .y in Fig. 3, or they may be of the uniform secion indicated by the dotted'lines 33 or of any preferred section. 1n any case the curved face 27 is provided with a peripheral arcuate groove 8 adapted to fit the size of pipe to Vbe bent. The depth of this groove must not be greater than its radius and may with advantage be slightly less, to avoid sticking of the pipe in the groove.

It is requisite that this groove lit the pi Je to be bent as otherwise the section of tie pipe will be distorted in bending. Thus a set of dies must be provided for each size pipe, and where the range of sizes is wide the cost of the dies is considerable, even thoughk one set may be utilized for bends varying widelyin radius. l have therefore provided a further improvement in the construction of the die which maires it available for any desired range Vof pipe sizes. This improvement comprises the provision of circumferential filler bloclrs or bushings, lmade iaaisi preferably of a tough and fairly hard metal, shaped on their lower side to lit into a relatively large groove and provided on their upper side with a groove adapted to receive a smaller pipe. One or more such bushings may be used, as indicated at 35, 36 and 37, and the step between the upper and lower face may be one or more pipe sizes. The length of the bushing should be substantial" ly equal to that of the face 27 of the die. Asthe bushings are in compression during the formation of the bend they may be lightly retained in the die, as by the countersunk bolt indicated at 38 or even by spring clips.

The shortest bend which may be made with any one set of dies in fully retracted position has, obviously, a radius equal to the effective length of the die, measured from its face to the center of revolution of the face plate. f In this.' position of the dies the root of the groove in adjoining segments describes a true arc.

Gn equally advancing the dies from the center of revolution the circle described vby revolution of the dies increases and, as the arc of the groove is fixed, the root of the groove no longer lies in the circle but touches it only at the high or central point. At thil same time, as the radii diverge the spacing of the high points which actually bear on the pipe is increased. Forthese reasons the en' largement of the radius of the bend by merely advancing the dies cannot be continued indefinitely as, if the space between the .bearing points is too great, a smooth bend will not be produced'. I have found, however. that in bending il" pipe, for example, l can produce with'a single set of dies, used in the above manner, perfect bends having radii varying from 13" up to 30 or more.

I claim .as my invention:

l. A pipe-bending machine including a face plate; means for revolving said plate; a pipe clamp attached to said plate; a plurality of segmental dies attached to said plate, said dies having a peripheral arcuate groove parallel to said plate and in alignment with said clamp; means for holding saidpip'e in contact with said groove as said plate and dies are revolve-d, and means for varying the distance from the center ofsaid face plate to the groove in said dies. .A

Q. A pipe-bending machine including a face plate; means for revolving said plate; a pipe clamp movably attached to the face of said plate; a plurality of segmental dies adapted to be attached to the face of said plate,said dies having aperipheral arcuate groove parallel. to said face, and means for arranging and m'aintainingsaid dies on said face in arcs of variable radius concentric with said face. i Y

3. A pipe-bending machine including a facev plate; means for revolvingsaid plate; a plurality of dies adapted to be attached to revolvable face plate, a bending die attac ed thereto and an idler roll cooperating'with said die to form a bend, meansfor holding.

said die and said roll in a fixed space relation comprising a support for said roll; a' steel shaft centrally projecting from said plate, a

strapV having a bearing box engaging said shaft, and means Vfor movably attaching the end of said shaft opposite said box to said support. Y v

5. In a pipe bending machine; an arcuate die divided into segments-said segments hav'- ing peripheral arcuate grooves adapted to register When said segments are assembled on a plane surface, means `for rotating said die segments, and means for varyingthelrradn of rotation.

' Y 6. In a pipe bendingkmachine; a die'hav-v ing a peripheral arcuate groove; means for rotating said die; means for varying the l radius of rotation of said die, and Va ller adapted to fit Within said groove, said filler being provided with a second groove parallel to said first groove but of smaller transverse radius. v Y t f In Witness that I Vclaim the foregoing I have hereunto subscribed day of March, 1930.

CHARLES FRANCIS. v

by name this 22nd 

